An
electric field
is a space around a charged particle where the particle exerts electric force on other charged particles. Because of their force fields, charged particles can exert force on each other without actually touching. Electric fields are generally represented by arrows, as you can see in the
Figure
below
. The arrows show the direction of electric force around a positive particle and a negative particle. For an animated diagram, go to this URL:
http://ocw.mit.edu/ans7870/8/8.02T/f04/visualizations/electrostatics/15-CreateField/CreateField_640.mpg

Interacting Electric Fields

When charged particles are close enough to exert force on each other, their electric fields interact. This is illustrated in the
Figure
below
. The lines of force bend together when particles with different charges attract each other. The lines bend apart when particles with like charges repel each other. At the following URL, play “Electric Field of Dreams” to experience interacting fields of two or more charged particles.
http://www.cabrillo.edu/~jmccullough/Physics/Electric_Forces_Fields.html

Note
: +q = positive charge and –q = negative charge

Q:
What would the lines of force look like around two negative particles?

A:
They would look like the lines around two positive particles, except the arrows would point toward, rather than away from, the negative particles.

Summary

An electric field is a space surrounding a charged particle where the particle exerts electric force.

When charged particles are close enough to exert force on each other, their electric fields interact. Particles with opposite charges attract each other. Particles with like charges repel each other.

Vocabulary

electric field
: Space around a charged particle where the particle exerts electric force on other particles.